Gleiser’s main thesis is that our observations yield only an “island of knowledge.” Thus there are limits to science’s ability to answer fundamental philosophical questions. These limits to our knowledge arise both from the tools we use to explore reality and the nature of physical reality itself. What we can know is limited by the speed of light, the uncertainty principle, the incompleteness theorem, and our own intellectual limitations. Recognizing these limits does not entail abandoning science and embracing religion. We should continue our scientific investigation of the nature of the cosmos, Gleiser argues, for by coming to know the universe we come to know ourselves.

Obviously, Gleiser is right—there are limits to scientific knowledge as the incompleteness theorem and uncertainty principle strongly suggest. As the island of our knowledge grows, so too does the ocean of uncertainty which surrounds it. Still, science gives us our best chance to understand the nature of the cosmos, and hence the most firm foundation upon which to understand the meaning of the cosmos.

Gleiser also argues that science and religion focus on the same question.

The urge to know our origins and our place in the cosmos is a defining part of our humanity. Creation myths of all ages ask questions not so different from those scientists ask today, when they ponder the quantum creation of the Universe “out of nothing,” or whether our Universe is but one among countless others, all of them exhalations of a timeless multiverse. The specifics of the questions and of the answers are, of course, entirely different, but not the motivation: to understand where we came from and what our cosmic role is, if any. To the authors of those myths, ultimate questions of origins were solely answerable through invocations of the sacred, as only the timeless could create that which exists within time. To those who do not believe that answers to such questions remain exclusively within the realm of the sacred, the challenge is to scrutinize the reach of our rational explanations of the world and examine how far they can go in making sense of reality and, by extension, of ultimate questions of origins.

Gleiser’s point here is uncontroversial—similar desires motivate creation myths and scientific cosmology. As for popularity, religious myths win hands down, but for those not attracted to religious answers, Gleiser’s suggestion is insightful. They must make epistemic judgments and reconcile themselves with whatever comfort limited knowledge provides. This may not be an easy way to live, but it is an authentic way. Surely that counts for something. Gleiser’s book makes for a thoughtful read on a timeless topic, especially when humans are in desperate need of new narratives to replace the old religious ones.